1. Field of the Invention
This invention relates to a fixing structure and a fixing tool for a corrugated tube which can prevent twisting or bending thereof when a wire harness using a flexible corrugated tube for wire protection is arranged in an bended manner along the side of an attaching side of a vehicle body.
2. Description of the Related Art
FIG. 12 shows a conventional fixing structure for a corrugated tube.
A corrugated tube 71 is made of synthetic resin and is formed in a shape of a thin cylinder. The corrugated tube 71 has circumferential concave grooves and convex strips arranged in parallel at regular pitches in a longitudinal direction. The corrugated tube is flexible. The corrugated tube with plural electric wires passed internally serves as a wire harness.
The corrugated tube 71 serves as a tube for protecting electric wires. The corrugated tube 71 is apt to flex together with the plural electric wires 72 according to a two-dimensional or three-dimensional curved panel 75 on the mounting side 74 of a vehicle body. This enhances workability of arranging the wire harness.
Some corrugated tubes may have a longitudinal slit, and some corrugated tubes may not have the longitudinal slit. In the corrugated tube 71 with the slit, the electric wires can be easily ushered into the corrugated tube 71. In the corrugated tube 71 with no slit, it is troublesome to pass the electric wires through the corrugated tube. However, the slit will not open and winding of a vinyl tape is not required.
A corrugated tube fixing tool (hereinafter simply referred to as a fixing tool) 76 is constituted as a clamp for clamping the corrugated tube 71 against a panel 75 on the mounting side. The fixing tool 76 is necessarily arranged at the bending portion on the mounting side of the vehicle body. The fixing tool may be a binding tool such as a band.
The fixing tool 76 is secured to the panel 75 on the mounting side 74 using a flexible clip or screw. The clamping clip has a pair of flexible clamping pieces and fixed in a hole of the panel 75. In the case of using the screw (not shown), the screw is inserted into the hole of a bracket of the fixing tool 76 and further passed into a screw hole of the panel 75.
The wire harness 73 is arranged on the curve of the mounting side of the vehicle body. The outer corrugated tube 71 is firmly secured to the mounting side 74 by a plurality of fixing tools 76 in the longitudinal direction so that the wire harness 73 is firmly secured to the mounting side 74. This prevents swing of the wire harness due to vibration while a vehicle is running and interference between the vehicle body (represented by (74)) and wire harness 73 and attendant alien sound.
The electric wires 72 within the corrugated tube 71 are protected from rainwater or dust by the corrugated tube 71. The electric wires 72 are extended along the vehicle body (74) to predetermined positions of an instrument panel, floor, door (hinge door or slide door) so that they are connected to the corresponding electric devices and auxiliary devices through a connector.
However, in the conventional fixing structure and fixing tool 76 for the corrugated tube, when the corrugated tube 71 is firmly secured by the fixing tool 76 in order to secure the wire harness 73 at the flexing position of the three-dimensional mounting side 74 of the vehicle body, the electric wires 72 and the corrugated tube 71 will be twisted while they are flexing. In this case, the corrugated tube itself suffers the twisting stress. This presents a problem of deformation or damaging of the corrugated tube 71 or opening of the slit. When the slit opens, the internal electric wires 72 may bust out and may be stepped on by a human""s foot, or otherwise water or dust may invade the opening portion.
Since the corrugated tube 71 suffers tension, the fixing tool 76 is apt to be pulled and come off. This leads to poor workability of its assembling into the vehicle body. Further, the fixing tool 76 may come off so that the wire harness dangles and generates interference with the vehicle body.
Further, where the wire harness 73 is greatly flexed for arrangement or largely swung at a fulcrum of the fixing tool 76, the end of the fixing tool 76, i.e. the opening portion from which the corrugated tube 71 is derived, the wire harness inclusive of the corrugated tube 71 is apt to flex. In this case, the corrugated tube 71 and the internal electric wires 72 are apt to be damaged.
In view of the above circumstances, an object of this invention is to provide a fixing structure and fixing tool of a corrugated tube that can prevent the twisting of the corrugated tube when the wire harness using the corrugated tube is securely arranged, thereby improving assembling workability, prevent the deformation or damaging of the corrugated tube or opening of the slit and opening of the slit which are attributable to the twisting, thereby assuring the function of the corrugated tube as a harness protecting tube, and prevent the coming-off of the fixing tool due to the tension of the corrugated tube.
Another object of this invention is to provide a fixing tool of a corrugated tube that can prevent a wire harness, i.e. corrugated tube and internal electric wires from being damaged where the wire harness is greatly flexed for arrangement, or greatly swung.
In order to attain the above objects, there is provided a fixing structure for a corrugated tube which is fixed on a mounting side of a vehicle body by a fixing tool, the corrugated tube being circular in section and having circumferential concave grooves and convex strips arranged alternately in its longitudinal direction of a wire harness, the corrugated tube and a plurality of electric wires passing through the corrugated tube constituting the wire harness, wherein the fixing tool includes slidable-contact supporting portions which are slidably engaged with the concave grooves of the corrugated tube so that the corrugated tube is supported rotatably in a circumferential direction by the slidable supporting portions.
There is also provided a fixing tool for a corrugated tube to a mounting side of a vehicle body, the corrugated tube being circular in section and having circumferential concave grooves and convex strips arranged alternately in its longitudinal direction, wherein the fixing tool includes a receiving part and a covering part for holding rotatably the corrugated tube in its circumferential direction, and the receiving part and the covering part have slidable-contact supporting portions to be slidably engaged with the concave grooves.
In such configurations of the fixing structure and fixing tool, where the wire harness with the corrugated tube which is circular in section is arranged on the two-dimensional or three-dimensional curved panel, even when twisting force is acted on the corrugated tube, the corrugated tube rotates circumferentially along the slidable-contact supporting portions of the fixing tool to absorb the twisting force. For this reason, undue twisting force is not acted on the corrugated tube. Thus, the deformation or damaging of the corrugated tube or opening of the slit for ushering the wire harness can be surely prevented. The pulling force due to the twisting of the corrugated tube is relaxed so that coming-off of the fixing tool from the panel can be prevented.
There is also provided a fixing structure for a corrugated tube which is fixed on a mounting side of a vehicle body by a fixing tool, the corrugated tube being circular in section and having circumferential concave grooves and convex strips arranged alternately in its longitudinal direction, the corrugated tube and a plurality of electric wires passing through the corrugated tube constituting a wire harness, wherein the fixing tool includes a rotating member having a circular outer periphery for the corrugated tube in its inside, and rotating member is held rotatably in a circumferential direction within a body of the fixing tool.
Preferably, the fixing tool further comprises a rotating member for fixing in its inside the corrugated tube which is oval in section, and the rotating member is held rotatably in a circumferential direction by the receiving part and the covering part.
Preferably, in the fixing tool for a corrugated tube to a mounting side of a vehicle body, the corrugated tube being circular or oval in section and having circumferential concave grooves and convex strips arranged alternately in its longitudinal direction, wherein the fixing tool includes a rotating member for fixing the corrugate tube in its inside and a receiving part and a covering part for rotatably holding the rotating member in a circumferential direction.
In these configurations, the wire harness with a xe2x80x9cflatxe2x80x9d corrugated tube which is oval in section is arranged on the two-dimensional or three-dimensional curved panel, even when twisting force is acted on the flat corrugated tube, the flat corrugated tube circumferentially rotates integrally with the body of the fixing tool. For this reason, undue twisting force or bending force is not acted on the flat corrugated tube. Thus, the deformation or damaging of the flat corrugated tube or opening of the slit for ushering the wire harness can be surely prevented. The pulling force due to the twisting of the corrugated tube is relaxed so that coming-off of the fixing tool from the panel can be prevented. Incidentally, since the corrugated tube may be either circular or oval in section, versatility of the fixing tool can be improved.
Preferably, a cam groove is formed in one of the body of the fixing tool and the rotating member and a projection which moves along the cam groove is attached to the other thereof so that the rotating member can move in the longitudinal direction of the wire harness while it rotates. Otherwise, the cam groove is formed in one of the rotating member, the receiving part and the covering part, and a follower projection which moves along the cam is formed in the other thereof.
In such a configuration, where the wire harness is extended from the vehicle body to the slide door, when the wire harness is twisted and pulled in the direction of opening/closing the slide door (particularly, when the slide door has been fully closed, the wire harness is pulled strongly), the rotating member can move in the longitudinal direction of the wire harness while it rotates. In this way, the wire harness is extended between the vehicle body and the slide door so that the pulling force is absorbed. In addition, since the wire harness is flexed with a great flexing radius, secular damaging of the wire harness, i.e. corrugated tube and internal electric wires can be prevented.
Preferably, the rotating member has an inside portion for immobily holding the corrugated tube, and the inside portion is decentered in an oblique direction so that the wire harness is flexible with a large flexing diameter in the oblique direction. Otherwise, the rotating member and inside portions of the receiving part and the covering part are tapered, and the inside of the rotating member is decentered in an oblique direction.
In such a configuration, when the wire harness is twisted and pulled in the direction of opening/closing the slide door, the rotating member rotates in the direction of pulling the wire harness, and the wire harness is flexed so as to be decentered in an oblique direction within the rotating member. In this case, as compared with the case the wire harness is not decentered, the flexing radius of the wire harness is increased. This prevents undue bending force from being acted on the wire harness, thereby preventing secular damaging of the wire harness, i.e. corrugated tube and internal electric wires. Incidentally, a combination of the extension and decentering of the wire harness prevents damaging of the wire harness more surely.
Preferably, the body of the fixing tool is provided with curved walls for the wire harness on a decentered side of the inside portion. In this configuration, since the wire harness derived from the rotating member in a curved shape is supported along the curved wall (e.g. at the tip of the curved wall), the flexing radius of the wire harness is defined largely, thus preventing the wire harness from being buckled, and hence preventing the corrugated tube and wires from being damaged more surely.
Preferably, the corrugated tube is oval in section. In this configuration, the fixing structure can be down-sized (low-profiled) by use of the flat corrugated tube. In addition, if the corrugated tube is caused to flex in a small-diameter direction when the slide door is opened/closed, the flexibility of the wire harness is increased, thereby preventing the corrugated tube from being damaged.
Preferably, the receiving part and the covering part have opposite semi-circular or arc concave portions, and the slidable-contact portions are formed at edges of each concave portions. In this configuration, the lower part of the corrugated tube is engaged with the concave portion of the receiving part whereas the upper part thereof is engaged with the concave portion of the covering part. Thus, the corrugated tube can be supported easily and surely by both concave portions, thereby improving the workability of assembling. Where the concave portions are formed on the walls on both sides of the receiving part and covering part, the corrugated tube can be held stably at two points in the longitudinal direction.
Preferably, the rotating member is divided into divisional members each having an inside portion which is circular or oval in section corresponding to a shape of the corrugated tube, and the inside portion has a convex strip to be engaged with one of the concave grooves of the corrugated tube.
In this configuration, since the flat corrugated tube which is oval in section is sandwiched by the divisional rotating members, it can be easily held, thereby improving the workability of assembling. Further, since the rotating member can be made divisional, the structure of the rotating member serving to fix the flat corrugated tube can be simplified and that of the mold for resin molding can be also simplified, thereby reducing the production cost.
Preferably, the rotating member has a convex strip and/or circumferential groove on its outer periphery and the receiving part and the covering part have a slidable-contact groove and/or slidable-contact convex strip which are to be slidably engaged with the convex strip and the circumferential groove.
In this configuration, since the convex strip and/or circumferential groove on its outer periphery of the rotating member and the receiving part are guided by the slidable-contact groove and/or slidable-contact convex strip of the receiving part and the covering par, the rotating member can be rotated smoothly and surely. Thus, the twisitng when the corrugated tube is arranged can be absorbed more surely.
Preferably, the cam groove has a starting point and an ending point with which the follower projection can be brought into contact.
In this configuration, when the rotating member is rotated by twisting of the wire harness, the ending point and starting point of the cam groove serve as stoppers for the projection. Namely, when the projection is brought into contact with the starting point or ending point of the cam groove, the further rotation of the rotating member, i.e. the twisting of the wire harness can be stopped, thereby preventing the electric wire or corrugated tube from being damaged due to undue twisting.
Preferably, the receiving part or covering part is provided with outward curved walls with which an outer surface of the corrugated tube is to be brought into contact so that the corrugated tube is prevented from becoming buckled. Further, the curved walls may be provided oppositely in a horizontal or vertical direction on the side of deriving the corrugated tube.
In this configuration, when the wire harness is flexed greatly so as to be arranged on the vehicle body, the outer surface of the corrugated tube is brought into contact with the curved wall of the fixing tool so that the wire harness is smoothly curved and rectified along the curved shape of the curved wall, thereby preventing the corrugated tube or internal electric wires from being damaged or deformed. This effect can be obtained also when the wire harness extended from the vehicle body to the slide door is swung largely as the slide door is opened/closed.
Preferably, the receiving part and covering part and the divisional members are rotatably coupled with each other using a hinge.
In this configuration, the operation of closing the covering part on the receiving part can be easily carried out, and the engagement of the slidable-contact supporting portion with the concave groove of the corrugated tube and that of the slidable-contact groove of the covering part with the groove of the rotating member can be improved. This improves and assures the operation of assembling.
The receiving part and the covering part are fixed by locking means. In this configuration, the operation of fixing the receiving part and the covering part can be carried out with one-touch of finger, thereby improving the workability of assembling.
Preferably, the receiving part is provided with a clamping clip to be securely inserted into a hole on a mounting side of a vehicle body.
In this configuration, the fixing tool can be easily secured to the vehicle body with the aid of the clamping clip. Further, since the clamping clip is rotatable within the hole of the vehicle body, the fixing tool is rotatable in the direction of flexing the corrugated tube. Thus, the tens ion of the corrugated tube can be absorbed or relaxed, thereby preventing the corrugated tube from being damaged or deformed due to flexing and the fixing tool from being come off.
The above objects and features of this invention will be more apparent from the following description taken in conjunction with the accompanying drawings.